Args argument in GraphQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the args argument in GraphQL resolver functions?

The args argument holds the input parameters passed by the client in a GraphQL query or mutation. It allows the resolver to access these inputs to fetch or modify data accordingly.

beginner

How do you define arguments for a GraphQL field in the schema?

Arguments are defined inside parentheses after the field name in the schema, specifying the argument name and type, for example: user(id: ID!): User. This means the field user expects an id argument of type ID.

beginner

In a resolver function, how do you access the args argument?

The resolver function receives <code>args</code> as the second parameter. For example: <code>function resolver(parent, args, context, info) {}</code>. You can then use <code>args.argumentName</code> to get the value passed by the client.

intermediate

Why is it important to validate args in GraphQL resolvers?

Validating args ensures the inputs are correct and safe before using them to query or update data. This prevents errors and security issues like injection attacks or invalid data processing.

intermediate

Can GraphQL arguments have default values? How does that affect args?

Yes, arguments can have default values defined in the schema, like limit: Int = 10. If the client does not provide a value, the resolver receives the default in args, so it can work without requiring all inputs every time.

In a GraphQL resolver, which parameter usually contains the client's input values?

A info

B args

C context

D parent

The args parameter holds the input arguments sent by the client in the query or mutation.

How do you specify an argument named id of type ID! in a GraphQL schema field?

A field(id: String)

B field(id: Int)

C field(id: ID!)

D field(id)

Arguments are defined with their name and type inside parentheses, e.g., field(id: ID!).

What happens if a client does not provide an argument that has a default value in the schema?

A The query fails with an error

B The resolver receives <code>null</code>

C The argument is ignored

D The resolver receives the default value in <code>args</code>

If an argument has a default value, the resolver gets that value in args when the client omits it.

Why should you validate args in your resolver?

A To prevent errors and security issues

B To speed up the query execution

C To change the schema dynamically

D To ignore client inputs

Validating args helps avoid errors and protects against malicious inputs.

Which of these is NOT a typical parameter of a GraphQL resolver function?

A database

B parent

C context

D args

Resolvers usually receive parent, args, context, and info. database is not a standard parameter.

Explain what the args argument is in GraphQL and how it is used in resolver functions.

Think about how you get user inputs in a function.

Describe how to define and use arguments with default values in a GraphQL schema and resolver.

Consider what happens if a client forgets to send an argument.